The numbers of men who have sex with men who are HIV-positive in the United States continues to rise, particularly in large urban centers such as New York City. As such, unique approaches to assessing psychosocial and sexual health and well-being of HIV-positive gay and bisexual men are crucial to developing interventions tailored to reducing sexual risk and substance use in this population. Disclosure of HIV status remains difficult for HIV-positive people due to stigma, and this difficulty is especially apparent within sexual situations. Both status disclosure and substance use have been investigated in prior research as variables that increase sexual risk (i.e. sex without condoms) among HIV-positive gay and bisexual men. During sexual encounters with non-main (i.e. new or casual) sexual partners, cognitive conflicts that result from fear of interpersonal rejection and intrapersonal shame are likely to influence the synergistic relationship between disclosure, substance use, and condom use. Building on the social psychological theory of cognitive dissonance, this investigation is based on a hypothesis that dissonance (i.e. conflict) is a negative state of arousal that motivates people to engage in behaviors to reduce that negative arousal. We hypothesize that interpersonal conflict (i.e., fear of being rejected for disclosing HIV-positive status and for using condoms) and intrapersonal conflict (i.e., higher levels of sexual shame) will interact to increase substance use and decrease both condom use and disclosure within sexual encounters. The primary goal of this study is to provide useful measurements of these constructs and examine these hypotheses to inform public health interventions aimed at reducing sexual risk and substance use. As such, the project focuses on two aims: (1) to establish reliability, validity, factor structure, and psychometric properties of three measures of intrapersonal and interpersonal conflict; and (2) to elaborate and test the relationship of interpersonal and intrapersonal conflict with HIV status disclosure, sexual risk, and substance use during sex with casual partners. The proposed project will be embedded into a larger study (R01MH87714, Parsons PI; referred to herein as the parent project), which is a longitudinal study that follows highly sexually active gay and bisexual men utilizing multiple methods to investigate their sexual risk behavior. The proposed project will add two internet-based assessments to the parent project that include both new and existing measures. We will combine these new measures with existing data to examine the psychometrics of the newly created measures and test the significance of the proposed hypotheses. The research and training plans proposed for this project are also designed to foster my development as a research scientist with a strong foundation in sexual risk, substance use, and research with HIV-positive gay and bisexual men.